Evaluation of Steam and Soil Solarization for Meloidogyne arenaria Control in Florida Floriculture Crops

Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in 2 yr of field trials on a commercial flower farm in Florida. The objective was to determine if preplant steam treatments in combination with solarization, or solarization alone effectively controlled nematodes compared to methyl bromide (MeBr). Trials were conducted in a field with naturally occurring populations of M. arenaria. Treatments were solarization alone, steam treatment after solarization using standard 7.6-cm-diameter perforated plastic drain tile (steam 1), steam treatment following solarization using custom-drilled plastic drain tile with 1.6-mm holes spaced every 3.8 cm (steam 2), and MeBr applied at 392 kg/ha 80:20 MeBr:chloropicrin. Drain tiles were buried approximately 35 cm deep with four tiles per 1.8 by 30 m plot. Steam application followed a 4-wk solarization period concluding in mid-October. All steam was generated using a Sioux propane boiler system. Plots were steamed for sufficient time to reach the target temperature of 70°C for 20 min. Solarization plastic was retained on the plots during steaming and plots were covered with a single layer of carpet padding to provide additional insulation. The floriculture crops larkspur (Delphinium elatum and Delphinium × belladonna), snapdragon (Antirrhinum majus), and sunflower (Helianthus annuus) were produced according to standard commercial practices. One month after treatment in both years of the study, soil populations of M. arenaria were lower in both steam treatments and in MeBr compared to solarization alone. At the end of the season in both years, galling on larkspur, snapdragon, and sunflowers was lower in both steam treatments than in solarization. Both steam treatments also provided control of M. arenaria in soil at the end of the season comparable to, or exceeding that provided by MeBr. Both steam treatments also reduced M. arenaria in snapdragon roots comparable to, or exceeding control with MeBr. Meloidogyne arenaria in soil increased in solarization alone. Solarization alone also had higher gall ratings on larkspur, snapdragon, and sunflower than all other treatments. Steam provided excellent control of M. arenaria in this study.     

Extraction enhancing mechanism of steam exploded Radix Astragali

Plant extraction occupies a vital status in the fine chemical industry, and steam explosion has been confirmed to be an effective pretreatment to enhance the extraction performance. In order to reveal the extraction enhancing mechanism of steam explosion, innovatively from the view of plant porous medium, we characterized porous properties of steam exploded Radix Astragali and established the correlation of porous properties and saponins extraction performance of Radix Astragali. The results indicated that average pore diameter was the most relevant to extraction parameters with R-square > 0.99 among various porous properties, which can effectively characterize the extraction performance. Area percentage of middle and large pores (100–100,000 nm) of Radix Astragali was increased from 8.25% to 91.57% after steam explosion and the increase of these pores was the major factor for enhancing extraction performance. Based on the close correlation of extraction parameters and porous properties, the extraction mechanistic model of steam exploded Radix Astragali was proposed. Altered porous properties improved the solute–solvent accessibility and internal mass transfer in the extraction process. Such findings are anticipated to prompt the enhancing effects and widespread application of steam explosion technology in plant extraction, and further identify research directions that lead to more efficient extraction.     

Volatile constituents in leaves of parsley

Volatile chemicals obtained from the leaves of parsley, Petroselinum sativum by steam distillation, isopentane extraction, and head-space analysis were identified by GLC-MS. The presence in leaf oil of α-pinene, β-pinene, myrcene, β-phellandrene, trans-β-ocimene, γ-terpinene, 1-methyl-4-isopropenyl benzene, and 1,3,8-p-menthatriene as shown by earlier investigators was confirmed. In the present studies, the number of volatile chemicals detected in the leaves was extended by an additional 42. Sniffing tests of effluent from a gas chromatograph of a concentrate from parsley leaves showed that 1,3,8-p-menthatriene was only one of several compounds that gave a parsley-like aroma.     

Influence of steaming explosion time on the physic-chemical properties of cellulose from Lespedeza stalks (Lespedeza crytobotrya)

The synergistic effect of steam explosion pretreatment and sodium hydroxide post-treatment of Lespedeza stalks (Lespedeza crytobotrya) has been investigated in this study. In this case, Lespedeza stalks were firstly exploded at a fixed steam pressure (22.5 kg/m²) for 2–10 min. Then the steam-exploded Lespedeza stalks was extracted with 1 M NaOH at 50 °C for 3 h with a shrub to water ratio of 1:20 (g/ml), which yielded 57.3%, 53.1%, 55.4%, 52.8%, 53.2%, and 56.4% (% dry weight) cellulose rich fractions, comparing to 68.0% from non-steam-exploded material. The content of glucose in cellulose rich residues increased with increment of the steaming time and reached to 94.10% at the most severity. The similar increasing trend occurred during the dissolution of hemicelluloses. It is evident that at shorter steam explosion time, autohydrolysis mainly occurred on the hemicelluloses and the amorphous area of cellulose. The crystalline region of cellulose was depolymerized under a prolonged incubation time. The characteristics of the cellulose rich fractions in terms of FT-IR and CP/MAS ¹³C NMR spectroscopy and thermal analysis were discussed, and the surface structure was also investigated by SEM.     

Graphical Procedure for Comparing Thermal Death of Bacillus stearothermophilus Spores in Saturated and Superheated Steam

The thermal death curve of dried spores of Bacillus stearothermophilus in saturated steam was characterized by three phases: (i) a sharp initial rise in viable count; (ii) a low rate of death which gradually increased; and (iii) logarithmic death at maximal rate. The first phase was a reflection of inadequate heat activation of the spore population. The second and third phases represented the characteristic thermal death curve of the spores in saturated steam. A jacketed steam sterilizer, equipped with a system for initial evacuation of the chamber, was examined for superheat during normal operation. Measurements of spore inactivation and temperature revealed superheat in surface layers of fabrics being processed in steam at 121 C. The high temperature of the fabric surfaces was attributed to absorption of excess heat energy from superheated steam. The superheated steam was produced at the beginning of the normal sterilizing cycle by transfer of heat from the steam-heated jacket to saturated steam entering the vessel.     

Volatile components of Artemisia monosperma and Artemisia judaica growing in the Egyptian deserts

Volatile components of Artemisia monosperma and of Artemisia judaica obtained by steam distillation of the fresh plants were analysed by capillary gas chromatography/mass spectrometry. Volatile oil of A. monosperma was found to be made up primarily of highly unsaturated hydrocarbons and aromatic acetylenic compounds with 3-methyl-3-phenyl-1,4-pentadiyne being the major component. Volatile oil of A. judaica, on the other hand, was found to be a mixture of esters, ketones and aldehydes in which pipertone is the major component.     

Isolation and structure of the sex-pheromone of the moth, Nudaurelia cytherea cytherea

The sex-pheromone of Nudaurelia cytherea cytherea has been isolated from the terminal segments of the female moth by solvent extraction, steam distillation, and column and gas-liquid chromatography. The structure was determined by infrared, nuclear magnetic resonance, and mass spectrometry as cis-dec-5-en-1-yl 3-methylbutanoate (isovalerate). The synthetic ester showed activity in field tests.     

Optimization of steam treatment as a method for upgrading rice straw as feeds

The objective of the present study was to study the effects of different conditions of steam treatment on nutritional value of rice straw (RS). The steam treatment was accomplished in a high pressure vessel at pressures 15, 17 and 19 kg/cm² for a range of treatment time (0, 5 and 10 min) at a water-to-straw ratio of 1:1. The effect was also studied of the amount of water added (0:100–50:50 (w/w)) on the nutritive value of treated RS, where treatment was conducted at 15 bar pressure for 5 min. The effects of steam treatment were evaluated in terms of dry matter loss, fibrous portions, sugar profiles and in vitro gas production (GP). Steam treatment increased water solubility of RS. There was no significant effect of steam pressure on dry matter loss, pH, fibrous fractions (NDF, ADF and hemicellulose), and sugar profiles (total and individual) in either water extracts or insoluble residues. Dry matter loss was however, significantly greater in longer treatment time (10 min) than in shorter time condition (0 and 5 min). In the water insoluble residues of the steam-treated straw, hexoses were dominantly higher than pentoses, indicative of the hemicellulose hydrolysis during treatment. Steam treatment of RS also resulted in an increased soluble carbohydrate content, which decreased with the increasing pressure and prolonged time. Compared with the untreated RS, the treated straw had a higher 24 h GP, and a faster rate of GP but the potential GP was similar. All these GP parameters tended to be higher at lower steam pressure and shorter time of treatment, though the effect was not significant (P>0.05). Significant differences (P<0.01) were found in all parameters between lower and higher amount of water added. Compared to the lower water-to-straw ratio (below 2:8), the treated straw at the high moisture had a lower dry matter loss (P<0.01), higher water soluble carbohydrates (P<0.01) and higher GP (P<0.01). From these results and considerations of energy economy, it is inferred that the optimal treatment condition is likely at a steam pressure of 15 bar for 5 min, and that water-to-straw of above 3:7 seem to be needed to obtain optimal treatment results.     

Endoscopically visible steam pop during high-energy laser pulmonary vein ablation

A 58-year-old woman with atrial fibrillation underwent laser balloon ablation at our centre. During 12 W ablation in the left superior pulmonary vein, a sudden steam pop was witnessed with displacement of the balloon catheter. Visualisation of the pulmonary vein antrum showed a red discolouration at the last ablation site.The endoscopically assisted laser balloon ablation system (EAS) is a relatively novel technique that is being used to perform pulmonary vein isolation (PVI) in the treatment of atrial fibrillation [1]. The EAS consists of a flexible, compliant balloon for sustained wall contact and a power adjustable laser beam for ablation independent of tissue contact.A 58-year-old woman underwent PVI with the EAS due to drug-refractory, symptomatic and paroxysmal atrial fibrillation. During 12 W ablation at the antrum of the left superior pulmonary vein (LSPV), a sudden steam pop was witnessed, with displacement of the EAS catheter (Fig. 1). Visualisation of the LSPV antrum showed a red discolouration, most likely a haematoma in the antral wall of the LSPV, at the last ablation site. A successful PVI was performed; the red discolouration was still present after 1 h. The patient did not develop symptoms related to the steam pop and echocardiography did not reveal any abnormalities.Open in a separate windowFig. 1Witnessed steam pop during endoscopically assisted ablation. Panel a displays the fifth ablation site in the left superior pulmonary vein (LSPV) where the steam pop occurred. The white ring of exposed tissue is a sign of optimal catheter-wall contact. Panel b displays the LSPV antrum directly after the steam pop. Note the red discolouration which was not present in panel a Steam pops are caused by overheating of myocardial tissue, exceeding 100 ℃, and are preceded by a shift in impedance levels, which cannot be measured with the EAS. Higher energy settings and higher contact force are known to increase the risk of steam pops. Steam pops can lead to tissue disruption and cardiac perforation [2]. However, steam pops appear to be a rare complication with reduced EAS energy settings, which we mostly used in 50 EAS patients, in whom no steam pops were observed [3].     

Effect of steam explosion pretreatment on pore size and enzymatic hydrolysis of poplar

The purpose of this study was to determine the effect of batch steam explosion pretreatment on the rate of subsequent enzymatic hydrolysis of hybrid poplar wood. This pretreatment was found to be effective as indicated by the fact that for many of the pretreatment conditions studied the glucose yield obtained after 24 h of enzymatic hydrolysis using enzymes from Trichoderma reesei And Aspergillus niger is in excess of 90% of the potential, whereas the corresponding yield from unpretreated substrate is only 15%. The effect of pretreatment is believed to be primarily due to the increase in pore surface area accessible to enzyme molecules. Measurements show a considerable increase in pore volume available to 5–9 nm solute probes. Pretreated wood that was subsequently oven-dried hydrolysed poorly and showed a reduction in available pore volume after drying. Xylans are readily hydrolysed to xylose during pretreatment and owing to decomposition the amount of xylose in solution after steam pretreatment decreases as the severity of the reaction conditions increases; the converse is true for glucose. We conclude that steam explosion pretreatment can be effective on hybrid poplar and that the quantitative results obtained can be used for process design.     

Nutritive value of thermoammoniated and steam-treated maize stover. II. Rumen metabolites and rate of passage

Chopped maize stover, ammoniated at ambient and elevated temperatures or steam treated, was evaluated with four Cheviot crossbred wethers fitted with permanent rumen fistulae in a 4 × 4 Latin square design. Treatments were: (i) control, 60% H₂O, ensiled for at least 40 days; (ii) 3% NH₃, 60% H₂O for 30 days at 21°C; (iii) 3% NH₃, 60% H₂O for 12 h at 90°C; (iv) steamed at 16.2 kg/cm² and 213°C for 4 min. The sheep received two meals per day at a restricted level of 90% of lowest ad libitum intake. The markers ⁵¹Cr-EDTA (100 μ ci) and ¹⁰³Ru-phenanthroline complex (10 μ ci) were used for the liquid and particulate phases, respectively. Samples for rumen metabolites were collected in each period at 0, 0.5, 1.0, 2.0, 3.0, 4.0, 6.0 and 8.0 h after the morning meal. On the following day, a mixture of the markers in 200 ml of demineralized water was infused into the rumen in a single dose and rumen fluid was sampled at specific times for 4 days.Rumen fluid pH tended to be lower with ammoniated stovers. High NH₃-N levels were maintained with ammoniated stovers, indicating gradual release of nitrogen. Total VFA tended to increase more with the thermoammoniated stover. Molar proportions of propionate increased (P < 0.05) and butyrate decreased (P < 0.05) with ammoniation. In contrast, steam treatment increased (P < 0.05) molar proportions of acetate and butyrate. The largest decrease (P < 0.05) for C₂ : C₃ acids occurred with thermoammoniated stover. Treatments with NH₃ or steam increased (P < 0.05) dilution rate. Mean retention time of particulate matter was decreased (P < 0.05) by treatment, being shortest with steamed material.     

Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility

Background

While advantages of biofuel have been widely reported, studies also highlight the challenges in large scale production of biofuel. Cost of ethanol and process energy use in cellulosic ethanol plants are dependent on technologies used for conversion of feedstock. Process modeling can aid in identifying techno-economic bottlenecks in a production process. A comprehensive techno-economic analysis was performed for conversion of cellulosic feedstock to ethanol using some of the common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. Detailed process models incorporating feedstock handling, pretreatment, simultaneous saccharification and co-fermentation, ethanol recovery and downstream processing were developed using SuperPro Designer. Tall Fescue (Festuca arundinacea Schreb) was used as a model feedstock.

Results

Projected ethanol yields were 252.62, 255.80, 255.27 and 230.23 L/dry metric ton biomass for conversion process using dilute acid, dilute alkali, hot water and steam explosion pretreatment technologies respectively. Price of feedstock and cellulose enzymes were assumed as $50/metric ton and 0.517/kg broth (10% protein in broth, 600 FPU/g protein) respectively. Capital cost of ethanol plants processing 250,000 metric tons of feedstock/year was $1.92, $1.73, $1.72 and $1.70/L ethanol for process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Ethanol production cost of $0.83, $0.88, $0.81 and $0.85/L ethanol was estimated for production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Water use in the production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment was estimated 5.96, 6.07, 5.84 and 4.36 kg/L ethanol respectively.

Conclusions

Ethanol price and energy use were highly dependent on process conditions used in the ethanol production plant. Potential for significant ethanol cost reductions exist in increasing pentose fermentation efficiency and reducing biomass and enzyme costs. The results demonstrated the importance of addressing the tradeoffs in capital costs, pretreatment and downstream processing technologies.     

The volatile phyllode oil of Acacia spirorbis

The steam volatile phyllode oil of Acacia spirorbis was found to be predominantly sesquiterpenoid in character. The most abundant sesquiterpenoids     

Novel extraction method of antioxidant compounds from Sasa palmata (Bean) Nakai using steam explosion

Antioxidant compounds were extracted from various parts of Sasa palmata (Bean) Nakai, a bamboo plant whose leaves are commonly used to wrap foodstuffs such as Sushi in Japan. Highest concentrations of antioxidant compounds existed in the leaf part of S. palmata. Steam explosion treatment followed by hot water and methanol extractions was used for separating the antioxidant compounds from S. palmata leaf. The steam explosion treatment is the physical–chemical treatment which crushes a sample by sudden reduction of the pressure in reactor to atmospheric pressure after steaming the sample at high temperature and pressures. Sasa palmata leaf was hydrolyzed by steaming and crushed by the rapid decompression. The optimal condition of steam explosion for the effective extraction of antioxidant compounds from S. palmata was determined as a steam of temperature of 250 °C and a steaming time of 1 min. In these conditions 217.41 mg/(g-Sasa leaf) of phenolic compounds and 142.81 mg/(g-Sasa leaf) of radical scavenging activity, that was expressed as butylated hydroxyanisole (BHA), were obtained.     

Outbreak of boils in an Alaskan village: a case-control study

Objective To determine whether taking steam baths was associated with furunculosis and to evaluate possible risk factors for the occurrence of boils during a large outbreak in Alaska. Design A cohort study of village residents, a case-control study, and assessment of environmental cultures taken from steam baths. Setting Village in southwestern Alaska. Participants 1 adult member from 77 of the 92 house-holds in the village was interviewed; 115 residents with at least one boil occurring between January 1 and December 12, 1996 were considered to be cases; 209 residents without a boil acted as the control group. All 459 village residents were included in the cohort study. Main outcome measure Rate of infection among all residents and residents who regularly took steam baths, risk factors for infection, and relative risk of infection. Results 115 people (25%) had had at least one boil. Men were more likely to have had a boil than women (relative risk 1.5; 95% confidence interval 1.1 to 2.2). The highest rate of infection was among people ages 25-34 years (32/76; 42%). No children younger than 2 years had had boils. Boils were associated with using a steam bath (odds ratio 8.1; 3.3 to 20.1). Among those who used a steam bath, the likelihood of developing boils was reduced by routinely sitting on a towel while bathing, which women were more likely to do, and bathing with fewer than 8 people. Of the 93 samples taken from steam baths, one Staphylococcus aureus isolate was obtained from a bench in an outer dressing room. Conclusion Using a steam bath was associated with developing boils in this outbreak in a village in Alaska. People should be advised to sit on towels while using steam baths.     

Does the effect of pelleting depend on the wheat sample when fed to chickens?

Experimental comparisons of the nutritional value of different wheat cultivars commonly use feeds in meal form even though the large-scale broiler producers use steam pelleted feeds. The aim of this experiment was to examine the effect of steam pelleting on the performance, dietary N-corrected apparent metabolisable energy (AMEn), total tract dry matter retention (DMR), nitrogen retention (NR) and fat digestibility (FD) coefficients, and digestive tract development of broilers fed four different wheat samples in complete diets. Four European wheat samples, with different chemical composition and endosperm characteristics, were used in a broiler experiment. The wheat samples were milled through a 5 mm screen and four basal feeds containing 670 g/kg of each selected wheat sample were mixed. The basal feeds were then split into two batches and one of them was steam pelleted resulting in eight experimental diets. Each diet was fed ad libitum to eight pens of two male Ross 308 broilers from 10 to 24 days of age. Feeding pelleted diets improved (P<0.001) feed intake and weight gain, and daily water intake of the birds. Pelleting also improved dietary AMEn and FD (P<0.001) and DMR (P<0.05). An interaction (P<0.05) was observed between wheat samples and steam pelleting for NR. Steam pelleting improved (P<0.05) NR in the wheat sample with high starch and protein and hard endosperm but not in the rest of the wheat samples. Similar interactions (P<0.05) were also observed between wheat sample and steam pelleting for gain to feed (G : F) and water to feed (W : F) ratios. Pelleting improved G : F ratio the greatest in the wheat sample with high starch and protein and hard endosperm. Feeding the same wheat sample also decreased (P<0.05) W : F but only in the mash diets. Regardless of the wheat sample the values of dietary AMEn did not differ (P>0.05). Feeding different wheat types and pelleting did not (P>0.05) change the development of the gastrointestinal tract of the birds. The study showed that there were differences between four wheat samples when they were fed in pelleted complete feed, but no differences were observed when fed in mash form complete diets. Research on the interaction between pelleting and wheat chemical and quality characteristics is warranted.     

Survey of the essential oil in Spartina cynosuroides

The essential oil of the giant cordgrass, Spartina cynosuroides, was isolated in 0.02”/ yield by steam distillation. Analysis by GLC-MS showed the     

Germacrone,a sesquiterpene repellent to obscure root weevil from Rhododendron edgeworthii

A steam volatile fraction from Rhododendron edgeworthii leaves inhibited obscure root weevil (Sciopithes obscurus) feeding on sucrose-treated membrane filters. The most prominent component in this fraction was the sesquiterpene germacrone. Germacrone was found to be an obscure root weevil repellent.     

An experimental study on biomass air-steam gasification in a fluidized bed

The characteristics of biomass air-steam gasification in a fluidized bed are studied in this paper. A series of experiments have been performed to investigate the effects of reactor temperature, steam to biomass ratio (S/B), equivalence ratio (ER) and biomass particle size on gas composition, gas yield, steam decomposition, low heating value (LHV) and carbon conversion efficiency. Over the ranges of the experimental conditions used, the fuel gas yield varied between 1.43 and 2.57 Nm3/kg biomass and the LHV of the fuel gas was between 6741 and 9143 kJ/Nm3. The results showed that higher temperature contributed to more hydrogen production, but too high a temperature lowered gas heating value. The LHV of fuel gas decreased with ER. Compared with biomass air gasification, the introduction of steam improved gas quality. However, excessive steam would lower gasification temperature and so degrade fuel gas quality. It was also shown that a smaller particle was more favorable for higher gas LHV and yield.     

Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation processes: Enzyme production for sugarcane bagasse hydrolysis

Cellulases and hemicellulases from Trichoderma reesei and Aspergillus niger have been shown to be powerful enzymes for biomass conversion to sugars, but the production costs are still relatively high for commercial application. The choice of an effective microbial cultivation process employed for enzyme production is important, since it may affect titers and the profile of protein secretion. We used proteomic analysis to characterize the secretome of T. reesei and A. niger cultivated in submerged and sequential fermentation processes. The information gained was key to understand differences in hydrolysis of steam exploded sugarcane bagasse for enzyme cocktails obtained from two different cultivation processes. The sequential process for cultivating A. niger gave xylanase and β-glucosidase activities 3- and 8-fold higher, respectively, than corresponding activities from the submerged process. A greater protein diversity of critical cellulolytic and hemicellulolytic enzymes were also observed through secretome analyses. These results helped to explain the 3-fold higher yield for hydrolysis of non-washed pretreated bagasse when combined T. reesei and A. niger enzyme extracts from sequential fermentation were used in place of enzymes obtained from submerged fermentation. An enzyme loading of 0.7 FPU cellulase activity/g glucan was surprisingly effective when compared to the 5–15 times more enzyme loadings commonly reported for other cellulose hydrolysis studies. Analyses showed that more than 80% consisted of proteins other than cellulases whose role is important to the hydrolysis of a lignocellulose substrate. Our work combined proteomic analyses and enzymology studies to show that sequential and submerged cultivation methods differently influence both titers and secretion profile of key enzymes required for the hydrolysis of sugarcane bagasse. The higher diversity of feruloyl esterases, xylanases and other auxiliary hemicellulolytic enzymes observed in the enzyme mixtures from the sequential fermentation could be one major reason for the more efficient enzyme hydrolysis that results when using the combined secretomes from A. niger and T. reesei.